Aeration of cesspools

ABSTRACT

Apparatus and methods for the aeration of cesspools in operation. In one embodiment there is a tool for inserting the aeration device under the bottom of the cesspool. The tool comprises a central cylinder with retractable arms. The aeration device has retractable arms which attach to the tool and compressed air is supplied to the tool to facilitate its passage through and beneath the pool. The tool is then removed leaving the aeration devices in place with a line extending out of the pool to receive compressed air. Other embodiments include the method of inserting the aeration device, a system for aerating a pool, and methods for controlling the operation of the aeration device.

This application is a continuation of application Ser. No. 692,387 filedon Jan. 17, 1985, now abondoned which in turn is a division ofapplication Ser. No. 514,935 filed on July 18, 1983, now U.S. Pat. No.4,494,616.

BACKGROUND OF THE INVENTION

This invention relates to apparatus and methods for the aeration ofcesspools and more particularly to apparatus and methods for convertinga static anaerobic operating cesspool system into a dynamic, aerobicwaste disposal system.

In most if not all urban and in many suburban areas of this country,liquid wastes are conveyed for disposal through networks of sewagepipes. However, in many communities involving millions of homes andplaces of businesses, individual cesspools are still relied upon for theultimate disposal of such wastes. A cesspool, as understood in the art,is a container planted usually beneath the surface of the ground, openon the bottom and frequently having openings in the side walls. Liquidwaste material is discharged into the container, with solid materialsettling on the bottom and the liquid percolating down through the solidmaterial collected on the bottom and same liquid seeping out through theside walls. A cesspool is effectively dead when the collected sludge onthe bottom and the side walls is so dense that inflow exceeds outflow ofthe liquid and cleaning of the pool is incapable of altering thatrelationship. Anaerobic bacterial action breaks down the digestiblesolid materials present thereby, in theory at least, extending the lifeof the cesspool.

In practice, however, the useful life of a cesspool is shortenedconsiderably by what actually occurs. Anaerobic bacterial action isinefficient and appears to be relatively ineffective in digesting muchof the materials which should be digested, and it is possible that someof the waste materials themselves, such as detergents and other cleaningmaterials, may inhibit such action. Furthermore, the operation of thecesspool itself creates conditions which reduce the percolation rate ofthe water with the result that very often and possibly in most cases,the pool becomes filled with liquid long before it becomes filled withsolid material. This results in cesspool overflow and backup problems.

The conditions in a cesspool which reduce the percolation rate and causethe problems described above involve the tendency of the solid andsemi-solid material settling out of the liquid waste to pack on thebottom in such a way as to interfere with the flow of liquid through it.The layer of this material gets thicker as it builds up and packs downunder its weight. Some of the smaller and finer parts of the digestedsludge intermix between the grains of sand and gravel forming the bedfor the pool and this increases the density of this underlying bedtherefore further restricting draining of the liquid. Constant flow ofthe liquid downwardly through the sludge and gravel beneath the bottomof the pool enhances packing of the solid materials which over a periodof time reduces the rate of percolation and eventually leads to cesspooloverflow and backup before being filled with solid material as describedabove.

This problem has long been recognized and there are certain techniquesin current use to cope with the situation. When a cesspool becomesfilled, a suction tube may be dropped into it and the liquid removed.Also, solid material can be agitated and removed along with the liquid.Under some conditions, workers can physically penetrate the pool withtools to scrape and remove the solid materials. These procedures aregenerally expensive and have to be repeated at frequent intervalsbecause the underlying conditions which inhibit drainage are notrectified, and the pool fills up rapidly with the waste liquid beinddischarged into it.

Another technique frequently employed to drain a pool filled with liquidis to dump large amounts of concentrated sulfuric acid through the wasteline. This is quite effective when first used but subsequent treatmentscan result in damage to the structure of the cesspool, and repeated usesare found to become less effective. In addition, the discharge of largeamounts of such acids into the ground water is frowned upon by manyenvironmentalists. Because such acids are heavy and sink rapidly to thebottom of the pool, this material will have no effect on an overflowpool which is in common use and required by many building authorities.

Elaborate arrangements for dealing with liquid waste products are shownin U.S. Pat. Nos. 1,398,394, 3,168,595, 3,828,933 and 4,376,702. Thesesystems are relatively complex and do not appear to be able to solve theproblems described above.

SUMMARY OF THE INVENTION

The present invention overcomes or reduces many of the present problemsof cesspools as described above by effectively substituting dynamicaction in a cesspool for the static type of action which is typical ofcesspools in general use today.

It has been found that by substituting aerobic bacterial action in thepool for the anaerobic type currently in use and physically maintaininga porous condition in the layer of solids being built up as well as inthe sand and gravel base for the pool itself the life of the cesspool isextended considerably. Furthermore, as aerobic action is considered tobe more effective and efficient in digesting that portion of the solidwaste which is capable of such treatment, there is far less solidmaterial in the liquid waste available for accumulating in the pool.

In this invention, there is provided an aeration system and method forbubbling up air through the pool either continuously or at intervals toprevent packing of the solid materials and so insure adequate drainagethrough the pool.

In preferred embodiments of this invention, there is provided a tool forimplanting an aeration device under an existing cesspool. Such a toolcomprises an extended hollow tube with a leading edge for penetratingthe cesspool and a handle at the other end, tubes communicating with theinterior of the hollow tube projecting from a side wall adjacent theleading edge and projecting forwardly past the leading edge, and armshinged on the hollow tube adjacent the leading edge and movable betweena retracted position up against the hollow tube and an expanded positionwhere the arms are flared outwardly. A mechanism is provided to insurethe arms move in unison and a rod extends from the mechanism to thehandle so that the position of the arms is known to the operator. Avalve is provided in the handle so that compressed air can be deliveredinto the hollow tube. A hose connected to the handle provides fordelivery of the air under pressure.

The aeration device has a body which is inserted into the leading edgeof the hollow tube of the tool and hollow flexible arms withperforations which rest on and are attached to the pivoted arms of thetool. With the arms retracted and the valve turned to permit air underpressure to enter the hollow tube the tool can be inserted down throughthe center of the cesspool to a point below the bottom of the pool.Compressed air emanating from the leading edge of the hollow tube, theprojecting tubes, and the flexible arms agitate the solid material andpermit the tool to reach the desired location easily and with littleeffort.

As the tool is removed the pivoted arms catch the solid material and arespread into their open position. An elastic band coupling the flexiblearms to the pivoted arms is designed to snap readily so that theaeration device with a central tube extending up and out of the pool isleft in place as the tool is removed from the pool. A hose is thenattached to the aeration device and air is delivered to the basematerial beneath the pool.

Bubbling of air up through the pool at regular intervals or when neededreestablishes and maintains adequate drainage through the pool, while,in addition, the presence of oxygen in the air establishes aerobicbacterial action causing digestion and liquefaction of some of the solidmaterial as described above. In another embodiment, a chemical additivemay be added to the compressed air being delivered to the aerationdevice in order to enhance the bacteriological action within the pool.

It is thus a principal object of this invention to provide apparatus foraerating pools for receiving solid waste material in a liquid carrier.

Another object of this invention is a method for establishing aerationin a waste pool.

Other objects and advantages of this invention will hereinafter becomeobvious from the following description of preferred embodiments of thisinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematized illustration of a cesspool with provision foraeration in accordance with the principles of this invention.

FIG. 2 is an isometric view of an aeration device.

FIG. 3 is an elevation view of a tool embodying the principles of thisinvention in a partially retracted position with an aeration devicemounted.

FIG. 4 is a view along 4--4 of FIG. 3.

FIG. 5 is a schematic illustration of a liquid level control system forthe operation of the aeration device.

FIG. 6 illustrates schematically a multi-pool arrangement embodying theprinciples of this invention.

FIG. 7 shows schematically the addition of an additive to a pool inwhich aeration is conducted according to the principles of thisinvention.

DESCRIPTION OF THE PREFFERED EMBODIMENTS

Referring to FIG. 1, there is illustrated a cesspool 12 mounted belowground level 14 having an aeration device 16 inserted beneath pool 12.

Cesspool 12, as is understood in the art, generally is made up of acylindrical body 18 with a cover 22 having a removable closure 23closing off an opening for access. Cesspool 12 is open on the bottom andinserted in the ground previously excavated to accommodate it. The earthis then backfilled against the outside of the pool and on top of cover22, leaving cesspool 12 empty and resting on a bed 24 of gravel and sandwhich may be prepared for this purpose. Pool 12 may be provided withopenings in side wall 18 to permit liquid to drain out through the sidesalthough the major part of drainage is down through bed 24. A sewer line26 empties into pool 12 as illustrated.

Aeration device 16 in accordance with the principles of this invention,as seen in FIG. 2, consists of a center tube 28 extending down throughclosure 23 terminating in an adaptor 29 from which extends a pluralityof arms 32, in this case four of them, extending at about a 90 degreeangle to tube 28 when in place. Arms 32 each consists of a shortflexible section 30 and a rigid section 31 with pores or a microporousplastic so that when compressed air is fed into tube 28 the air emergesfrom arms 32 as indicated by the arrows. Flexible sections 30, as willbe seen later, makes it possible to fold up arms 32. If device 16 isinstalled when cesspool 12 is installed, then device 16 can becompletely rigid in construction.

However, when in accordance with this invention, aeration device 16 isinstalled where pool 12 is already in place, in many cases years afterits original installation, aeration device 16 must be constructed, asalready described, so that arms 32 are foldable up against tube 28 aswill be seen from the description given further below.

Referring back to FIG. 1, center tube 28 of aeration device 16terminates at a point 34 above pool 12 where a tube or conduit 36 to theoutlet of a compressor 38 is connected. Compressor 38 deliverscompressed air to aeration device 16 and the air under pressure bubblesup from arms 32 through bed 24 and the liquid and solid contents ofcesspool 12 as previously described.

In order to install aeration device 16 into an existing cesspool, aspecial tool embodying principles of this invention is utilized.Referring to FIG. 3 for details of the tool, it is seen that tool 40consists of an elongated metal cylinder 42 open at its bottom end 44 andterminating at its upper end in handle 46. Handle 46 is a hollow member,communicating with cylinder 42, closed at one end by a cap 48, andadapted at its other end to be connected to an air hose 52 which isconnected to a compressor for the delivery of compressed air to cylinder42. Mounted on handle 46 is a valve 54 operated by a lever 56. Byoperation of the latter, delivery of compressed air to tool 40 may becontrolled by the operator at handle 46 as he uses the tool.

The length of cylinder 42 is adjusted by the insertion and removal ofsections 57 and adapters 57a and 57b. Passing through a compressionfitting 46a in handle 46 into cylinder 42 is a push rod 60 with a stop60a on the bottom which can be moved up and down by manipulating asother end for a purpose to be described later.

Adjacent the bottom of cylinder 42 are four equally spaced brackets 58with pins 59 on which four arms 62 are mounted at one for pivoting. Eacharm 62 is V-shaped in cross section as seen in FIG. 4 for a purposewhich will later become obvious and is provided with a pair of spikes 64and a flat plate 66 at its other end. Any other cross section of arms62, such as dished, may be employed as long as it is able to perform thefunction to be described below. A bracket 68 with a pin 72 pivotallysupports one end of a rod 74 on each arm 62 and at its other end ispivotally attached to a floating ring 76 surrounding cylinder 42. Fromthis arrangement it is seen that movement of ring 76 along the length ofcylinder 42 will both cause arms 62 to move outwardly or inwardly inunison, and indicate to the operator the position of arms 62. Movingring 76 upwardly will cause arms 62 to retract against cylinder 42. Fora purpose which will later become obvious spikes 64 are each providedwith a sharp edge facing upwardly. In order to determine the position ofring 76 from handle 46, an extended rod 78 is provided with one endattached in any convenient fashion to ring 76 and directed parallel toand along the length of cylinder 42, terminating at some pointconvenient to handle 46.

Adjacent the free end of rod 78 is an index plate 79 on cylinder 42which indicates to the operator by the position of the free end of rod78 along plate 79 the location of ring 76 and hence the position of arms62. Rod 78 may be provided with add on sections to compensate for theaddition of one or more sections 57 to cylinder 42.

In order to mount aeration device 16 on tool 40, center tube 28 isinserted into cylinder 42 from the bottom as far as it will be able totravel. A locking screw 80 threaded through a side wall of cylinder 42is used to hold tool 16 firmly in place.

Arms 32 of device 16 are bent upwardly as illustrated in FIG. 3 and eacharm is fitted into the depression shaped in each arm 62. An elasticmember or rubber band 82 is pulled over the bottom of tool 40 and placedas illustrated at the locations of spikes 64 which perform the functionto hold these bands in place. With arms 62 fully retracted againstcylinder 42, tool 40 is ready to be utilized to place aeration device 16in place beneath cesspool 12.

A plurality of tubes 81 communicating with the inside of cylinder 42come out of the latter and are bent to terminate with open ends belowthe bottom end 44 of cylinder 42.

In order to use tool 40 to place aeration device 16 below cesspool 12 asshown in FIG. 1, tool 40 with device 16 mounted as in FIG. 3 with armsfully retracted against cylinder 42 is raised above the ground. As isunderstood in the art a tripod or other suitable crane-like device may,if desired, be used to support tool 40 in its raised position.

The ground above closure 23 is excavated and the latter is removed. Tool40 is lowered until it rests on the solid material on the bottom of pool12. Air valve 54 is then opened so that compressed air entering handle46 passes down into cylinder 42, around and through center tube 28. Theair passing around tube 28 leaves cylinder 42 through its bottom openingand out through tubes 81. The air entering center tube 28 enters arms 32and leaves through the pores or other openings along their length.Compressed air coming out of the bottom of cylinder 42 and tubes 81agitates the solid material so that very little effort is required forthe tool to pass through the bottom of pool 12. The tool is lowereduntil it reaches a point where bottom 44 is about 60 inches below thebottom of pool 12. This can be readily determined by using a dip stickto measure the distance to the bottom of the pool whereas the length ofcylinder 42 and its sections 57 are already known.

When tool 40 comes to rest at the desired depth, the rate of compressedair flow can be reduced by partially closing valve 54. Tool 40 is thenraised using the tripod and a suitable chain drive to gain a mechanicaladvantage. Plates 66 offer resistance to movement in the sand and gravelbase causing arms 62 to spread as cylinder 42 is raised, requiring inmany cases a substantial force to raise tool 40. As arms 62 spread,rubber band 82 become taut, and the knife edges of spikes 64 cut theband. Eventually arms 62 with arms 32 of device 16 become fully extendedat substantially right angles of cylinder 42 as is indicated by theposition of the end of rod 78 along plate 79. Locking screw 80 is thenloosened and T-member 61 on rod 60 pushed downwardly to loosen device 16from tool 40. Arms 62 continue to rotate downwardly as tool 40 is raisedwith arms 62 ultimately extending down as tool 40 is raised above groundlevel. Withdrawal of tool 40 leaves aeration device 16 in place as shownin FIG. 1 with the free end of tube 28 being at some predeterminedconvenient location, usually just above ground level as seen in FIG. 1.Then hose 36 is connected to tube 28 so that compressed air from thecompressor can be delivered whenever desired. Cover 23, with a hole toaccommodate tube 28, is replaced (prior to attaching hose 36) and theearth is backfilled above cesspool 10.

The distance at which aeration device 16 is placed below cesspool 12 isnot critical except that it should be at least eighteen inches belowpool 12. To obtain this positioning of device 16, when using tool 40, ithas been found that its leading edge should be lowered to about five orsix feet below pool 12. Then it rises about three feet before arms 62are spread out at right angles to cylinder 42. When tool 40 is finallyremoved, device 16 is found to be somewhere between eighteen inches andthree feet below its pool.

The length of arms 32 is also not critical. For a pool eight feet indiameter an optimum length for each arm 62 is about seventeen inches.This is the shortest length which produces sufficient diffusion of theair leaving the arms to aerate the whole pool. A greater length is notnecessary but does require a tool 40 with longer arms 62 and thus a muchheavier tool.

It should also be noted that arms 32 are hollow and are plugged at theirends to insure that the air diffuses through openings or pores in thewalls of the arms. A microporous plastic, available commercially, hasbeen found to be suitable for the rigid sections 31 of arms 32.

It is understood that compressor 38 can be manually controlled todeliver air continuously or at regular intervals to the aeration device16, much like the control of an automatic sprinkling system using atimer.

In addition, control over delivery of compressed air to the pool may beexercised based upon the level of liquid within.

Such a system, illustrated schematically in Fig. 5, includes abelow-ground cesspool 112 containing solid and liquid waste 114 andhaving mounted for use an aeration device 116 as previously describedwhose center tube 128 is connected to a compressor 130 through a line132.

A three wire level indicator strip 134 is located on tube 128 extendingfrom the top of the inside of pool 112 to some convenient intermediatepoint in the pool. Strip 134, as is understood in the art, consists of acenter common conductor running the full length, a second conductorrunning the full length, and a third conductor extending a shortdistance down from the top of pool 112. When the level of liquid 114reaches indicator strip 134, an electrical connection is made betweenthe first conductor and the common conductor. When the level reaches thethird conductor then there is also conduction between the thirdconductor and the common conductor.

There are several modes of operation to select from in this system shownin FIG. 5. In one mode, when the level of liquid 114 reaches the thirdconductor, compressor 130 can start to operate and not stop until thelevel drops below strip 134. In another mode, when the level reaches thefirst conductor, compressor 130 can operate at less than capacity, andshould the level continue to rise, compressor operation can be increasedwhen the level reaches the third conductor. This type of level indicatorand control as a system by itself is conventional and readily available.

Apparatus for installing and operating equipment for aerating a pool hasbeen described in connection with a single pool. In many cesspoolinstallations it is not unusual to have a cesspool with an overflowpool. In such a case, aeration device 16 or 116 would preferably beinstalled under the overflow pool in a one pool installation, or, ifdesired, aeration devices could be installed under both pools. In thecase of multipool installations of the aeration device, which wouldinclude not only a pool with an overflow, but also two or more poolsfrom different users such as what might be found in a commercialinstallation, it is possible to employ a single compressor to serviceall of the cesspools.

Referring to FIG. 6, for such an installation, there is shown a buildingor buildings 150 having a common waste line 152, a cesspool 154, andthree overflow pools 156, 158, and 162 containing aeration devices 16a,16b, and 16c, supplied by air lines 156a, 158a, and 162a, respectively.A compressor 164 under control of a timer 166 supplies air to a threeposition valve 168 under control of a sequencer 172. In the operation ofthis system, timer 166 turns on compressor 164 to operate for a fewpreselected hours each day or other period desired. The compressed airis delivered to valve 168 which has three outlet positions, one to eachof lines 156a, 158a, and 162a. Under the control of sequencer 172, thevalve 168 is positioned to deliver to each of the lines one at a timecompressed air to the three aeration devices. The valve and controldevices just referred to are by themselves well known in the art andcommercially available.

One of the advantages of the aeration systems herein described is theability to deliver chemical additives to a cesspool in a more effectivefashion than just dumping the chemicals in the pool because of thethorough distribution throughout the pool which takes place in theaeration systems just described and also to make the insertionautomatically without the necessity of opening the pool.

One such system, referring to FIG. 7, shows aeration device 16 connectedto compressor 180 through a venturi feeding device 182 and under controlof a timer 184. The chemical additive, which may be any one of a numberof enzymes found to stimulate aerobic bacterial action within acesspool, is supplied from a source 186 through a valve 188 undercontrol by a rate controller 192 for setting the rate at which theadditive is supplied. As is understood in the art, the additive iscarried by the compressed air either in a mist form, or gaseous,depending on the nature of the additive. Venturi device 182, as well asrate controller 192, is well known in the art and such devices areavailable commercially.

It is thus seen that there has been provided systems and methods for theaeration of cesspools, and devices and methods for inserting aerationdevices under existing pools. While a variety of certain specificpreferred embodiments of this invention have been described, it isunderstood that many other variations and changes in such systems,devices, and methods are possible without departing from the principlesof this invention as defined in the claims which follow.

What is claimed is:
 1. A system for aerating a cesspool forreestablishing drainage comprising a cesspool open at the bottom andresting on a bed of material for drainage of liquid out of cesspool downthrough the open bottom thereof and through said bed of material,aeration means located under said cesspool embedded completely withinsaid bed of material for bubbling air under pressure up through said bedand into said cesspool through said bottom thereof, and compressor meansfor delivering air under pressure to said aeration means forreestablishing drainage through said cesspool and said bed of material.2. The system of claim 1 in which said aeration means comprises a devicehaving arms to recive said air under pressure and means to dischargesaid air in the form of bubbles into said bed of material over an arealocated under said cesspool.
 3. The system of claim 1 having meansextending down through the inside of said cesspool into said bed ofmaterial for delivering air under pressure from said compressor means tosaid aeration means.
 4. The system of claim 1 having means in responseto the level of liquid waste therein to cause the operation of saidcompressor means when said waste rises above a predetermined level andto terminate operation of said compressor means when said liquid wastedrops below a predetermined level.
 5. The system of claim 1 having meansto add a chemical additive to said air under pressure.
 6. The system ofclaim 1 having means to time the operation of said compressor means soas to operate said aeration means at predetermined time intervals. 7.The system of claim 1 having more than one of said cesspools each havingsaid aerating means, and means to sequence the operation of saidcompressor means so that the aerating means for each of said cesspoolsis operated in a predetermined sequence.
 8. A method of aerating acesspool which is open at the bottom and rests on a bed of material sothat during normal operation of said cesspool liquid waste collectedtherein drains down through settled waste material and said bed ofmaterial, comprising the steps of placing an aerating device under saidcesspool completely embedded within said body of material, and supplyingair under pressure to said device to diffuse said air under pressure upthrough said bed of material and said settled waste material into saidcesspool through said bottome thereby maintaining drainage downwardly ofliquid waste in said cesspool.
 9. The method of claim 8 in which saidair under pressure is supplied to said aeration device through a tubepassing down through said cesspool into said bed.
 10. The method ofclaim 8 in which said air is supplied only when the liquid waste withinsaid cesspool reaches a predetermined level.
 11. The method of claim 8in which said air is supplied at predetermined intervals of time. 12.The method of claim 8 in which a chemical additive is added to said airunder pressure.